Permanent magnet and process of making the same.



nnrnun J. wnnn, or new YORK, N. Y., ASSIGNOR 0F ONE-HALF T0 EUGENE W. CALI?) WELL, OF NEW YORK, N. Y.

PERMANENT MAGNET AND PROCESS OF MAKING- THE SAME.

messes,

No Drawing.

To all whom itmag concern:

Be it known that I, ARTHUR J. WEED, a citizen of the United States, and resident of the city, county, and State of New York, have made certain new and useful Inventions Relating to Permanent Magnets and- Processes of Making the Same, of which the following is a specification.

This invention relates to permanent magnets and processes of making the same, especially by the treatment of iron castings at a low heat in the presence of cobalt salts or compounds, preferably in a closed chamber. 1

Iron and other magnetic materials, such as iron castings of various grades especially hard low grade cast iron, maybe given a high degree of permanent magnetism after first treatingthem in the proper way with suitable cobaltous or other similarly acting sensitizing material. For this purpose the iron castings may be heated for a suflicient time to a suitable temperature capable of efifecting the desired sensitizing action preferably for several hours or so to a tem'pera ture somewhat below that of a visible red varnish or other medium in which the finely heat in the presence of suitable cobaltous sensitizing material which may be conveniently efi'ected while the iron, for instance,

is surrounded by sand or the like in a closed chamber. The sensitizing material which may with good efi'ect be in the form of a mixture of about equal parts of black mid of cobalt, and red cobaltous sulfate may be applied. to the iron castings by any suitable powdered cobaltous material is incorporated. With small castings of a few pounds, such as are suitable for use in magneto machines the cobaltous material maybe applied to about the-thickness of an. ordinary coat of a paint or the magnet after having been varnished with shellac or the like may be Clipped into .a finely pulverized mixture of the cobalt sensitizing salts or the like, or

they may be brought into suficiently close grades of hard cast iron so that they may.

contact with the iron during the treating process. Thereafter the magnet may be covered with sand in a cast iron or other suitable treating chamber. and kept at a dull heat just below a visible red and then allowed to slowly cool which has a desirable annealing and softening action. with many Specification of Letters Yatent.

nection with Patented May 16, ll iliiiu Application filed June 21, 1!?09. Serial N 0. 503,330.

magnetized in any desired manner. This' sensitizing treatment seems to efiect some combination or union of the cobaltous sensltizing material'with the iron or to efiect some molecular rearrangement of its con- 'stituents so as to render it much more susceptible to and capable of permanently retaining considerable magnetic properties' Many other forms of cobalt material, such as metallic cobalt or the chlorids, for instance, seem to have a similar sensitizing action on ferreous magnetic material and may be used either alone or in combination with the sensitizing materials indicated.

Having described this invention in con a number of illustrative ingredients, proportions, steps and methods treatment, to the details of which disclosure theinvention isnot of course to be limited, what is claimed as new and what is desired to be secured by Letters Patent is set forth in the appended claims.

1. A permanent magnet composedof annealed cast iron which contains, in its superficial portions, a trace of cobaltous material, whereby it is capable of retaining magnetism to a considerably higher degree than similar cast iron which. contains no such cobaltous material.

cobaltous sensitizing material, whereby it is capable of retaining magnetism tola considerably higher degree than similar cast iron which contains no such cobaltous ma terial. I

'3. The process of forming a permanent magnet capable of retaining a high degree of magnetization which consists in bringing sensitizing material into intimate contact with a hard iron casting and in heating the same at a temperature approximately that of a visible redheat in a substantially closed treating chamber and in slowly cooling and annealmg said casting to facilitate its machlning and finishing and in magnetizing said casting, substantially as described;

at. The process of forming a permanent magnet capable of retaining a high degree of magnetization which consists in bringing oobalt sensitizing material comprising substantially equal parts of cobalt oxid and cobaltous sulfate into intimate contact with a hard iron casting and in heating the same for time in a substantially closed chamber at a temperature somewhat below a visible red heat and in cooling and magnetizing said casting.

6. The process of forming a permanent magnet capable of retaining a considerable degree of magnetization which consists in heating an lI'OIl casting for a considerable time in intimate contact with cobalt sensitizing material and in cooling and magnetizing said casting.

7. The process of forming a permanent magnet capable of retaining a high degree of magnetization which consists in heating a ferreous casting for a considerable time at a sensitizing temperature somewhat below a visible red heat in the presence of cobalt casting.

8. The process of treating ferreous magnetic material so as to be capable of retaining a high degree of magnetization which consists in heating said material for a considerable time at a sensitizing temperature somewhat below a visible red heat in the presence of cobalt sensitizing material. 1

9. The process of softening an iron casting and rendering the same capable of retaining a high degree of magnetization which consists in heating said casting for a considerable time at a sensitizing temperature somewhat below a visible red heat in the presence of cobalt sensitizing material and in gradually cooling said casting.

10. The process of rendering ferreous magnetic material capable of retainin a high degree of magnetization which consists in heating said material for a considerable time at a sensitizing temperature capable of rendering active cobalt sensitizing substance while said material is in the presence of said sensitizing substance and in cooling said material.

- ARTHUR J. WEED. Witnesses:

HARRY L. DUNCAN, Jnssm B. KAY.

sensitizing material and in magnetizing said- 

